Remember for a di hybrid cross with two completely heterozygous parents, the phenotypic ratio will always be 9:3:3:1
9 will always display both dominant traits, black and rough hair. 3 will display black hair and smooth hair and 3 will display not black hair and rough hair and 1 will display both receive traits
Use the pH color scale. It shows acidity level of both acids and bases. You dip one of the pH strips into whatever liquid you choose, and then compare the new color of the pH strip to the colors on the scale. This will tell you the level of acidity. pH scale can be found below. As you can see, the brighter colors are more acidic than the darker and duller colors.